|
GENERAL INFORMATION
Coast Electronics Compost Monitors are powered by two rechargeable/ replaceable 1.25 Volt Nickel Metal Hydride (NiMH) C-size Batteries. A battery charger is supplied with each instrument. Data storage is accomplished using memory chips which retain their memory in the event of a total power failure (non-volatile).
Battery charging is accomplished by plugging the 9VDC battery charger into a power source and into the power in jack located on the underside of the instrument. The monitor is equipped with an RS232 port through which the instruments can be programmed with sample placements and from which data can be downloaded from or uploaded to a computer.
There is no ON/OFF switch on Coast Electronics Compost Monitors. The monitor can be turned on (awakened) by pressing the green front panel touch pad. Battery conservation is accomplished by automatically powering down after a 10 minute period of inactivity. All Coast Electronics Compost Monitors contain Temperature and Oxygen Sensors. The Pro model also contains a C02 Sensor. Field replacement and calibration of the sensors is made possible by using calibration gas for C02 and a ice water bath and steam for temperature. The temperature and moisture analysers should never need field re-calibration by a user. The Oxygen sensor has a life of 1 to 2 years and is auto-calibrated using 20.9% (dry) ambient air.
Gas samples are drawn from the probe and through the gas sensor via an internal pump.
A liquid crystal display and associated touch pads provide user interface to all instrument functionality. Users are provided with methods of logging windrow measurements. A computer link mode of operation is provided for use in communicating with a computer in order to download monitoring protocol(s) and upload data to the computer after measurements have been made. An auto calibration mode is provided for quick adjustment of the instruments to current ambient gas conditions and a known calibration gas. A View utility mode is provided to allow the user to check firmware revision number.
MODE OF USE
The physical aspect of using the monitor consists of firstly ensuring that the sample inlet is shut off by twisting and locking the sample vent handle. The probe tip is then thrust into the compost windrow using the manipulating handles, much like using a garden fork. Try to make a fairly neat hole in order to ensure that you are sampling gas from inside the pile, not gas which gains access from the surface of the pile. Push the probe in to the required depth (foot rings are marked on the shaft). Unlock and open the sample vent by twisting and pulling up slightly the sample vent handle. Turn the unit on, make sure you are set to measure the required sample pile, position (segment) and depth…then RUN your sample (takes just over a minute). Shut the sample vent, pull out the probe and move to the next sample position. Repeat the process again. Before taking a new sample, you have the option of seeing what the last sample values were at that site…. simply by briefly tapping the red button. If the tip or sample vent become particularly messy or clogged you can wash them down using water from an outside tap or hose (or convenient puddle!!). The tip is made from solid stainless steel, so should be very durable. Beware of stabbing toes or scratching floors, however. Try to avoid storing or resting the probe in places where it could topple onto a hard (concrete?) surface. We make the unit rugged, but there are limits!!
OPERATIONAL MODES
1=Run sample test mode
2=cal mode (for oxygen auto-calibration)
3=temperature unit mode
4=PC RS232 mode
5=Adjust pile
6=Adjust position
7=Adjust depth
Differences between Excalibur1 and Excalibur2
1) Unit is easier to assemble, disassemble, replace oxygen cell, adjust.
2) Batteries are retained more securely, removing any risk of cracking the case (this sometimes occurred with Excalibur1). We recommend use of NiMH batteries for best performance when a rechargeable solution is wanted. Alkaline batteries give longest runtime.
3) Case is now all stainless steel, very rugged and weatherproof when held upright….IP67
4) RS232 link to PC now added. Required software may take a little longer to develop but hardware is in place. Uses a standard 2.5mm stereo jack to 6 pin D-type cable.
5) Charger socket added to facilitate use of rechargeable batteries without needing to remove them. Uses a cheap, standard 9VDC unregulated ½ amp or similar mains adapter fitted with a ‘2.5mm’ DC jack plug.
6) Moisture is now measured using a fast reliable method at the tip (excalibur1 used a complex relative humidity related method measured after the sample was pumped to the top box).
7) Samples will eventually be capable of being stored in the unit’s internal non-volatile store and downloaded to the PC.
8) On/off switching now performed more intelligently using the new control panel buttons and LCD display.
9) Unit is now menu-driven by 4 selectable menus displayed on the LCD. It is very easy to operate.
SPECIFICATIONS
SYSTEM CONTROLLER
Processor Type: 8-bit Microcontroller
Display: 16 x 2 line Super-Twist Liquid Crystal
Functions: Calculation and display of Moisture, Temperature, Oxygen, sample timing, flow control. Data logging and user interface. Storage of general functional parameters and Calibration Data
Serial Link: RS232 protocol at baud rate of 9600 bit /s with use of software handshaking. 1 start, 1 or 2 stops, no parity.
TEMPERATURE SENSOR
Measurement Range: 0 to 100oC
Accuracy: Typically ±0.5oC
OXYGEN ANALYSER
Measuring Principle: Single Electrochemical fuel cell.
Absolute Range: 0 to 25 percent Oxygen Concentration. Intrinsically linear
MOISTURE ANALYSER Measuring Principle: Proprietary electrical method. Firmware interpreted and linearized.
Absolute Range: 0 to 100 % Soil Moisture content
Supply Voltage: Nominally +3vdc using 2 off C-size zinc-carbon, Alkaline (best lifespan) or NiCAD / NiMH (both types rechargeable…NiMH are best choice). Charger +9VDC incoming supply to suit locally available voltage.
Power Requirement: <2 VA
Fuse Rating: n/a
MECHANICAL SPECIFICATIONS
Weight 3Kg Approx.
Dimensions: 1345 x 390 x 110mm (4’5” x 15 ½” x 4 ¼”)
Operating Temperature Range: 10 to 40 0C
Connections….
The Compost Monitor has two sockets mounted on its case underside, next to the sample gas outlet. The DC Jack takes battery charger input of +9VDC (tip positive)
The 2.5mm stereo jack connection provides an RS232 connection to a host PC computer. The tip is the serial data input to the Excalibur2. The sleeve is the serial data output from the Excalibur2. The shank is the 0V return connection. The cable has a 9 pin D-type female connector to plug straight into a standard IBM PC serial port.
|
